391668391536 has 40 divisors (see below), whose sum is σ = 1025670431760. Its totient is φ = 128767689216.

The previous prime is 391668391531. The next prime is 391668391561. The reversal of 391668391536 is 635193866193.

It is a self number, because there is not a number n which added to its sum of digits gives 391668391536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391668391531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55885251 + ... + 55892258.

It is an arithmetic number, because the mean of its divisors is an integer number (25641760794).

Almost surely, 2^391668391536 is an apocalyptic number.

It is an amenable number.

391668391536 is an abundant number, since it is smaller than the sum of its proper divisors (634002040224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391668391536 is a wasteful number, since it uses less digits than its factorization.

391668391536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111777593 (or 111777587 counting only the distinct ones).

The product of its digits is 18895680, while the sum is 60.

The spelling of 391668391536 in words is "three hundred ninety-one billion, six hundred sixty-eight million, three hundred ninety-one thousand, five hundred thirty-six".